In order to fabricate an integrated circuit the various lithographically defined fabrications levels must be aligned to each other. In optical lithography, a layer of photoresist on a substrate is exposed to actinic radiation through a patterned photomask that is aligned to an alignment target on the substrate. Structures fabricated in earlier lithographic fabrication steps serve as these alignment targets for alignment marks on the photomasks. Electron beam lithography, by contrast is a direct-write process, there are no photomasks and the electron beam is scanned across an electron beam resist layer. For each fabrication level, the electron beam must be registered to a reference structure. In general, optical lithography is fast but cannot print images on very small pitches. Electron beam lithography can print images on very small pitches, but is slow. The benefits derivable from merging of these two technologies is hindered by the fact that electron beam lithographic systems cannot register to current optical alignment structures. Therefore, there is a need for an alignment target and method for co-alignment of optical and electron beam lithographic fabrication levels.